Radiation isomerization



Oct. 18, 1960 P. J. LUCCHESI ET'AL 7 2,956,940

RADIATION ISOMERIZATION Filed April 29. 1957 NORMAL PARAFFINIC 3 5 HYDROCARBON FEED 6 Y e c| 4 ISOPARAFFINS RADIATION 1 kl SOURCE 4 PRODUCT 6 t SEPARATION DILUENT Peter J. Lucchesi Inventors Carl E. Heath By 56 a. M Attorney United States Patent RADIATION ISOMERIZATION Peter J. Lucchesi, Cranford, and Carl E. Heath, Nixon,

N..I., assignors to Esso Research and Engineering Company, a corporation of Delaware Filed Apr. 29, 1957, Ser. No. 655,906

12 Claims. (Cl. 204--162) This invention relates to the isomerization of hydrocarbons, and more particularly, to the production of saturated branched-chain hydrocarbons by the reaction of paraffinic hydrocarbons with a Friedel-Crafts type catalyst, in particular, aluminum chloride, in the presence of high energy ionizing radiation. The products are normally liquid saturated branched-chain hydrocarbons boiling chiefly within the motor fuel boiling range, i.e. 85 F. to 440 F.

Straight-chain paraflins of at least 4 carbon atoms per molecule heretofore have been isomerized in the presence of Friedel-Crafts type catalysts to produce branchedchain paraffins. Numerous elforts have been made in the past to minimize the degradation of the catalyst, as well as the degradation of the feed stock oil in contact with the catalyst. In general such efforts together With various attempts to increase the efliciency and to alter the selectivity of isomerization catalysts have met with little success.

In commercial operations, petroleum refineries have large quantities of light hydrocarbon mixtures available. However, there recently has sprung up a greater demand for the isoparaflinic hydrocarbons than for the normal parafiinic hydrocarbons, making it necessary to incorporate isomerization facilities in the ordinary refinery in order to obtain increased amounts of the isoparaifins which serve not only as blending agentsfor the normal paraifins, but also as intermediates and reactants in the" preparation of normally liquid hydrocarbons and which also are useful in motor fuels. For such purposes, often particular isomeric products are necessary.

The present invention provides for the isomerization of hydrocarbons, particularly paraflin hydrocarbons, to pro- 1 duce isomers thereof under conditions such that the ultimate yields of the desired isomers amount to almost quantitative proportions. The invention is based upon the discovery that the isomerization reaction conditions do not have to be materially altered chemically in order to I successfully enhance catalytic activity and beneficially alter catalytic selectivity.

In accordance with the present invention, paraflinic hydrocarbons having at least 4 carbon atoms, and preferably between about 4 and 8 carbon atoms, per molecule are isomerized in the presence of from about 2 to 200 wt. percent based on the weight of paraffin of aluminum chloride catalyst by exposing the catalyst in contact with the parafiinic hydrocarbon at a temperature in the range of about 40 to 300 F. to high energy ionizing radiation until at least about l l0- kwh. of radiation per pound of parafiin has been absorbed.

In one embodiment of the invention, pure straightchain paraflin hydrocarbons are employed as the feed stock for the process which has been discovered. For example, normal butane, normal pentane, normal hexane, normal heptane and the like, as pure compounds, can be subjected to the isomerization treatment as hereinafter more fully described. The process of the present invention equally as well applies to the treatment of hydrocarbon mixtures predominantly composed of straightchain paraflinic constituents. For example, straight run naphthas of low octane number, preferably those having narrow boiling ranges, can be isomerized according to the process of the present invention to improve their octane number markedly and to bring about other desirable changes in their characteristics. Likewise, normally gaseous parafiinic mixtures such as field butanes, paraffinic mixtures resulting from the removal of olefin constituents of refinery C cuts, waste gases of paraffinic nature evolved from thermal or catalytic alkylation processes and similar sources of mixed paraflinic hydrocarbon material can be utilized as suitable feed stocks in the present process. I

The invention is not limited to the isomerization of straight-chain hydrocarbons but includes also the conversion of branched-chain parafiins to isomeric, more highly branched hydrocarbons. Mixed parafiins such as light virgin naphthas can, by the present method, be converted into isomeric mixtures which have an increased value with respect to anti-detonation qualities'when used as motor fuels. In general, any hydrocarbon feed stock composed predominantly of paraffinic hydrocarbons, that is, comprising at least wt. percent paraflinic constituents, is suitable for use as a feed stock for the process herein outlined. Particularly advantageous for this process is a feed stock containing at least 75 wt. percent based on the total weight of hydrocarbon present of paraffins having from 4 to 8 carbon atoms and boiling in the range of from about 30 to 200 F. Typically, other constituents which may be present will include benzene, naphthenes, such as cyclohexane and methylcyclopentane, and the like. A product containing substantial amounts of branched-chain isomers can be separated from the reaction medium and fractionated within the desired boiling range. The unconverted constituents can thenbe returned to the isomerizing reactor as by recycling to be further isomerized to more useful products.

The isomerization reaction of the present invention is carried out by exposing the reactants and the isomerization catalyst to high energy ionizing radiation,that is, high energy quanta (radiation wave length less than 50 A.), neutrons, and charged and uncharged particles of atomic and sub-atomic nature having energies greater than about 30 electron volts. Advantageously, types of radiation employed for the purposes of invention include high energy electromagnetic radiation such as gamma rays and X-rays and high velocity electrons, as well as beta rays and alpha particles. These types of radiation may be supplied by naturally-occurring radioactive materials which emit alpha, beta and gamma rays. Fission by-products of processes generating atomic power or fissionable materials which emit high energy gamma rays afford a highly desirable and most abundant source of radioactivity suitable for the purposes of the invention. These by-products include those with atomic numbers ranging from 30 to 63 and'their compounds. They are formed in the course of converting uranium and thorium and other fissionable materials in an atomic reactor. By high energy ionizing radiation is meant, radiation from terrestrial sources of sufiicient intensity such that the dose rate is at least l 10- kwh./lb. of reactant/hr. This excludes radiation such as cosmic and ultraviolet which are ineffectual for the purposes of this invention.

Materials made radioactive by exposure to neutron irradiation, such as radioactive cobalt-60, which emits gamma rays, can likewise be used. Suitable sources of high velocity electrons are the beams of electron accelerators, such as the Van de Graafi electrostatic accelerator. In general, however, high velocity electrons, X-rays, and high energy gamma rays and their wellknown-sources, such as nuclear fission by-products and "materials made radioactive by neutron irradiation, are

preferred for the purposes of the invention mainly because of the relatively high penetrating power of the rays and the availability and ease of application of these sources of radiation.

For isomerization reactions in accordance with the present invention, a wide radiation dose range can be employed, for example, from about to about 10 kwh./ lb. of paraflin. Preferably, the radiation dose utilized is between about 10* and 10 kwh./lb. This is approximately equal to a dosage of 10 to 10 megaroentgens. Suitable temperatures include those from about 40 to 300 F. The higher temperatures, that is, from 150 to 300 F., are preferably employed when the feed stocks are in vapor phase. At lower temperatures, for example, from 40 to 150 F., isomerization can be elfected in the liquid phase and without appreciable side reactions. The time of the reaction varies with other factors such as temperature, the amount of catalyst, the particular catalyst used and the particular feed stock treated. In general, however, the time of reaction can be from /2 to 30 hours, and the conditions are usually adjusted so as to obtain a high conversion at a temperature of, for example between 100 and 200.

The surprising feature of the novel process of this invention is that at radiation dosages of between about 10- and 10 kwh./lb. of parafiin, a conversion product can be obtained in which the concentration of unconverted paraflin has been reduced by about 30 to 95%. Generally, at least 50% of the original paraffin reacted is converted to more valuable products by this process.

The amount of catalyst to be used varies widely, depending upon the particular hydrocarbon which is to be converted. Preferably, an amount in the range of about 2% to 200% by weight, based on the weight of hydrocarbon material present in the reactor, is employed.

The reaction is preferably carried out under liquid phase conditions, hence any temperature below the critical temperature of the feed stock can be employed, although it is preferable to use the temperatures specified above. Sufl'icient super-atmospheric pressure can be employed to maintain the parafiin reactant as well as the reaction products in the liquid phase under the reaction conditions obtained. In particular, liquid phase operations are conducive to the production of ultimate high yields and to the carrying out of the process in a continuous manner. The aluminum chloride can be added to the feed before it enters the reactor. It is to be understood, however, that the process is not only applicable to continuous operations, but it is contemplated to carry the same out in batch type apparatus for single batch operation. Where the reaction is carried out in the liquid phase, it is advantageous to intensively agitate the reaction mixture so that intimate contact is established between the feed and the catalyst. The catalyst can be employed as a slurry and a mechanical agitator propelled by an external means inserted in the reactor can be used. Where a bed type of catalyst is employed, it is well to employ liquid phase operation and to force the liquid hydrocarbon feed into the reactor under pressure.

The invention can also be practiced by employing a continuous batch-type of operation in which the reaction is carried out in liquid phase, and the liquid product is removed after each batch reaction and distilled or passed through a molecular sieve adsorption zone, to separate the isomerized product. Unconverted paraffins can then be returned to the reactor in a subsequent charge. Preferably a recycle type of operation is employed.

The isomerization catalyst can be produced in situ by the reaction of a suitable metal such as aluminum with chlorine or a compound chemically reacting as the equivalent of free chlorine under the conditions of the reaction or may be added to the feed stock as chemically pure anhydrous aluminum chloride or as a commercial prod-- not. It can be advantageous to have present within the reactor small amounts of catalyst known to promote the formation of Friedel-Crafts type of reagents. Such materials are hydrogen-ion producers, metals such as rrnercury or mercury salts, small amounts of water or hydrogen halide acids, or the like. The presence of small amounts of olefins in the isomerization reaction zone, together with the attendant formation of liquid olefinaluminum chloride complex, also results in increased yields of the desired isomers. In another modification, a catalyst bed can be made up of Porocel or some other suitable highly porous alumina and placed within the radiation zone. The catalyst mass employed can be formed by admixing granules of aluminum chloride with the desired quantities of dehydrated Porocel and the mass heated while passing through a stream of inert vapor. Preferably aluminum chloride, which is but sparingly soluble in hydrocarbons, is employed as the isomerization catalyst for the process of the present invention. Aluminum bromide particularly is less desirable since it leads to excessive cracking. This is believed to be attributable to the relatively high solubility of aluminum bromide in hydrocarbon mixtures.

No special type of apparatus is required for carrying out the novel isomerization process of this invention. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation will be understood more clearly and fully from the following description considered in connection with the accompanying drawing.

Referring to the drawing in detail, it will be seen that aluminum chloride is mixed with the normal paralfinic hydrocarbon to be converted and admitted to the process by line 1. In this manner the catalyst is fed into the radiation reactor zone 3. A suitable support can be employed within the radiation zone on which the aluminum chloride lays down. Advantageously, this support comprises a highly porous alumina of the Porocel type. Additional amounts of aluminum chloride are added from time to time if necessary by line 1.

The aluminum chloride-parafiin mixture is exposed to high energy ionizing radiation in the radiation zone 3. A suitable source of radiation comprises atomic waste products obtained from nuclear reactors or atomic piles. This material can be suitably enclosed or concentrated as in an underground storage area, and the hydrocarbon mixture can be passed through or around the waste material.

The radiation zone can advantageously comprise a cobalt-60 source. Electron accelerators of the linear type and Van de Graalf generators can also be employed as a source of high energy electrons. The electrons are directed through a thin reinforced window into the hydrocarbon-aluminum chloride mixture.

The converted material is removed by line 4 and passed into a suitable product separation zone. This zone can comprise, for example, a distillation zone, a solvent extraction zone, an absorption zone, a molecular sieve, or a combination of any of these.

Preferably, the product separation zone 5 comprises a molecular sieve having pore openings of about 5 A. It has been known for some time that certain zeolites both naturally occurring and synthetic and sometimes termed molecular sieves have the property of separating straightchained from branched-chained hydrocarbon isomers, as well as from cyclic and aromatic compounds. These zeolites have innumerable pores of uniform size, and only molecules small enough to enter the pores can be absorbed. The pores may vary in diameter from 3 or 4 A. to about 15 A. or more, but it is a property of these zeolites or molecular sieves that any particular product has pores of substantially uniform size. Zeolites may vary somewhat in composition but generally contain the elements, silicon, aluminum, and oxygen as well as an alkali metal or an alkali earth metal. A large number of naturally occuring zeolites having molecular sieve activity, that is the ability to absorb a straight-chained hydrocarbon and exclude or reject the branched-chained isomers and aromatics because of diiferences in molecular size, are described in an article entitled, Molecular Sieve Action of Solids, appearing in Quarterly Reviews, volume III, pages 293320, 1949, published by the Chemical Society, London. Molecular sieves suitable for the present invention comprise sieves having pore openings in the range of from about 4 to 10 A. The molecular sieve heretofore described is arranged in any desired manner in the adsorption zone of separation zone 5. It can, for example, be arranged on trays or packed therein with or without support. Conditions maintained in the molecular sieve treatment in adsorption zone 5 are flow rates of about 0.1 to about 5 v./v./hr., temperatures of about 200 to about 350 F. and pressures from atmospheric pressure to several p.s.i.g. With molecular sieves of the indicated size of pores, the normal paraflins contained in the feed are readily absorbed while the isoparaflinic product is not, but instead is passed by line 6 to suitable product containers. Unconverted normal parafiinic constituents are recovered readily by the utilization of molecular sieves and returned by recycle process to the reactor by line 2 as indicated.

In some instances it may be desirable to employ dilucuts in the alkylation process in order to control the amount of conversion. These are introduced by line 7 into the feed prior to its entering the reaction zone. Generally, any common diluent present in an amount between about 1.0 and 10% by weight based on the weight of total hydrocarbon present which is substantially inert to high energy ionizing radiation is suitable for this purpose, for example, highly refined mineral oil, such as white oil or benzene, advantageously can be employed.

In order to more fully disclose the invention, the following examples are given to indicate the nature of the invention, however, it should be distinctly understood that these examples are presented merely as illustrative of the specific types of operation of the invention.

EXAMPLE 1 Normal hexane in the amount of 125 ccs. was placed in a 635 cc. steel reactor and contacted with AlC1 in an amount of about 150% by weight, based on the total hydrocarbon present in the reactor. The inhomogeneous system was exposed to cobalt-60 gamma rays of an intensity of about l.5 l roentgens per hour for a duration sufiicient to result in the adsorption by the reaction system of 71.2 megaroentgens (mr.) of ionizing radiation. In a second run, a radiation dose of mr. was employed. The radiation yield, G(n hexane) (molecules of feed hexane reacted per 100 E.V. of radiation absorbed) was equal to 75 at the higher dose, 500 at the lower dose. The conversion is compared with that obtained for the same reactant system in the absence of radiation (Table I).

Example 1 clearly demonstrates the surprising increase in the conversion of normal hexane, which is obtained by the method of the present invention. In the absence of radiation, the product yield based on n-hexane *6 in the feed was 61.4 weight percent The conversion obtained by the present method is seen to have been 963 and 92.8 weight percent for two runs at widely difiering radiation doses. 7

Of particular importance in the present invention was the discovery that by employing high energy ionizing rays to greatly enhance conversion in aluminum chloride-isomerization reactions, it is possible to materially alter the specificity'of the aluminum halide catalyst. This feature of the invention is illustrated by Example 2.

EXAMPLE 2 V A feed stock comprising normal hexane was irradiated under conditions similar to those'of Example 2, with a cobalt-60 gamma source'inthe' presence of AlCl (wt. ratio of catalyst/feed, f1,5) At atmospher-ic pressure and 115 F., a radiation-dose of-7l.2 megaroentgens gave a radiation yield of G =75. The measured total conversion of n-hexane was 96% by weight. By comparison, the reaction under conditions which were identical, except that the reaction mixture was not irradiated, with gamma rays, resulted in a total conversion equal to only 56.4 weight percent. Analysis of the product yield of both reactions revealed the surprising discovery that n-hexane can be converted in high yields to isobutane and isopentane by cobalt-60 irradiation in the presence of A101 (Table II).

Table 11 The surprising efliect on the selectivity of the catalyzed isomerization can be seen from the comparison of the yields of isobutane and isopentane for the reactions of Example 2. In the absence of radiation, 13.7 percent by weight of the total product yield was isopentane. For isobutane inthis case, the product yield was 8.9 percent. The conversion reaction utilizing high energy ionizing radiation gave a product in which the yields of these two valuable materials was increased 31 and 183 percent respectively. The importance of this inventive process cannot be underestimated. Isomeric branched-chain C and C hydrocarbons have great utility, particularly in the oil industry. These hydrocarbons are most useful as front endblending components for high octane motor fuels. Their utility lies in their high octanes and their volatility... Such hydrocarbons are also extremely useful as feed stocks for catalytic alkylation to higher boiling branched hydrocarbon fuels.

Further beneficial-'alteration-of the specificity of the isomerization catalyst in accordance with the method of this invention has also been observed by comparing 7 the composition of the liq uid products produced in reactions such as the ones described in Examples 1 and 2. Analysis of the liquid product of the A101 catalyzed isomerization of parafliirs in the presence of high energy ionizing radiation has shown hydrocarbon compositions strikingly diiferent than that obtained by conversions in i the absence of ionizing radiation.

EXAMPLE 3 iclentical to the first except that high energy ionizing rays were not absorbed by the reaction mixture, was also "analyzed for liquid product.

The composition of liquid product for the reaction with and without radiation is given in Table III.

Table III Liquid Composition, Wt. Percent With Without Radiation Radiation Unreacted n-hexane 5. 1 45. 8 Ca isomers 36. 28.0 2,2-dimethyl butane 18. 3 8. 9 2-methyl pentane cyclopentane l 13. 7 14. 5 2,3-dimethyl butane l 3-methyl pentane. 4. 5 4. 6 Other liquid products 2 58. 4 27. 2

1 Analysis by vapor-liquid partition chromatography does not distinguish between these compounds.

1 C4, C5, C and C isomers.

The above example clearly shows the increased selectivity of AlCl catalyzed isomerizations of n-hexane to 2,2-dimethyl butane in accordance with this invention. This novel process resulted in an increased conversion of alkane, a higher yield of C isomers, and at the same time resulted in an increased yield of the valuable highly branched isomer, 2,2-dirnethyl butane while the nonirradiated product contained only 32% of the isomer. The highly branched hexane isomer, 2,2-dimethyl butane or neohexane, is an extremely elfective motor gasoline component in the C range because of its high octane number.

EXAMPLE 4 High energy ionizing radiation can be used to convert normal paraffins having from 4 to 8 carbon atoms to more valuable conversion products with high yields. The product yields obtained with and without gamma radiation at dosage in the range of from 10- to 10 kwh. per pound of hydrocarbon in the presence of aluminum chloride are compared in Table IV below for five, six and seven carbon paraflins. Utilizing 1.5 guns. AlCl gm. paraffin irradiations were carried out at 115 F. at 1 atm. pressure.

The above example shows that a paraffinic hydrocarbon having about 4 to 8 carbon atoms in contact with about 2 to 200 wt. percent based on the weight of paraffins of aluminum chloride can be converted in high yields to branched-chain isomeric hydrocarbons by exposing the aluminum chloride in contact with the paraffinic hydrocarbon at a temperature of about 40 to 300 F. to

high energy ionizing radiation until at least about 1 10- kwh. of radiation energy per pound of paraffin has been absorbed.

Conversions of alkane significantly increased over those obtained without the aid of radiation can also be obtained using moderate reactive conditions by utilizing other types of high energy ionizing radiation. For example, X-ray irradiation can be used to promote isomerization of normal paraffins in the presence of, for example, anhydrous aluminum chloride. Example 5 is given to illustrate such a process. Typical experimental results are reported in Table V.

EXAMPLE 5 A mixture of normal hexane, A1Cl (0.4 wt. ratio catalyst/paraffin), and HCl (0.2 wt. percent) was irradiated for 16 hours with 55 kv. X-rays provided by the K alpha line from tungsten. The reaction proceeded smoothly at F. at a pressure of 1 atmosphere. The product yield, consisting mainly of six-carbon isomers, isopentane, isobutane and cyclohexane was 60.8 wt. percent on feed. This was compared with a yield of only 5.7 wt. percent for the same reaction in the absence of radiation. In addition to the liquid product, a small amount of gas, mostly hydrogen and isobutane, was formed. The composition of the liquid product was analyzed and is given in Table V.

Table V [Product composition (Example 5)] With Without Compound Radiation, Radiation,

Wt. Wt. Percent Percent n'hexane 39. 2 94. 3 lsohexane 23. 1 1. 6 2,2-dimethyl butane-.- 6. 0 0. 2 Z-methyl pentane L cyclopentane 1 l2. 7 1. 0 2,3-dimethyl butane 1 3-methyl pentane 4. 4 0. 4 isobutane.-.- 8.5 0.0 isopentane. 10. 8 0. 0 2,3-dimethyl pentane 4 8 1 0 cyclohexane 1 Other liquid products 13. 6 3.1

Analysis by vapor-liquid partition chromatography does not distinguish between these compounds.

The experiments reported in Example 5 clearly demonstrate that X-ray irradiation can be used to promote isomerization of normal paraffins in the presence of aluminum chloride in accordance with the present invention. It can be seen that 60.8 wt. percent of the reactant feed was converted by this novel radiation process, whereas with the known process employing aluminum chloride alone, the yield was only 5.7 wt. percent. The calculated radiation yield for this reaction was Gubhexane =40,000. This is a truly surprising result when compared with the radiation yield for normal hexane in the absence of aluminum chloride. For this latter reaction, Gmmexane) is less than 10.

Another feature of the present invention resides in the discovery that benzene can be added to normal paraflinaluminum chloride mixtures in low concentration to control the selectivity and increase the radiation yield from radioisomerization. Concentrations of benzene suitable for the purposes of this invention are from about 0.1 to 10 wt. percent based on the weight of the parafiin. This eifect is illustrated by Example 6.

EXAMPLE 6 A feed solution containing 99.25 parts by weight of hexane and 0.75 part benzene was irradiated by a cobalt- 60 source in the presence of aluminum chloride. The weight ratio of the catalyst to hexane was 1.5. The radiation yield G=(hexane molecules reacted per E.V.) was 427. Irradiation of nontreated feed gave a G value of 75. The product yield obtained when nor- 9 mal hexane was reacted in the presence of aluminum chloride with and without benzene is given in Table VI.

1 VLPC Analysis does not distinguish between these compounds. 2 Mostly i04 and i015. 3 C4, C5 and 07+.

The above example shows that radiation yields are increased and selectivity is controlled by the addition of a small amount of benzene to normal hexane-aluminum chloride mixtures under radioisomerization conditions. A high yield of 2,2-dimethyl butane was obtained with minimum degradation to gas. Without treatment with benzene, 27.7 wt. percent of feed was cracked to isobutene and isopentane. Cracking has been eliminated in the benzene-promoted reaction. Furthermore, the primary C isomer was the highly valuable 2,2-dimethy1 butane. It is seen that without irradiation, the primary isomer was 2-methy1 butane.

It is to be understood that the above-described arrangements and techniques are but illustrative of the application of the principles of the invention. Numerous other arrangements and procedures may be devised by those skilled in the art without departing from the spirit and scope of the invention.

What is claimed is:

1. A radiation isomerization process which comprises contacting a paraflinic hydrocarbon having from about 4 to 8 carbon atoms with about 2 to 200 wt. percent based on the weight of paraffin, of aluminum chloride, and exposing said aluminum chloride in contact with the paraflinic hydrocarbon at a temperature in the range of about 40 to 300 F. to high energy ionizing radiation until a total dosage in the range of l0- to 10 kwh. of radiation energy per pound of paraflin has been absorbed.

2. A radiation isomerization process which comprises contacting a paraffinic hydrocarbon having from about 4 to 8 carbon atoms with aluminum chloride in the amount of about 2 to 200 wt. percent based on the weight of paraflin, adding from about 0.1 to 10 wt. percent based on the weight of paraffin, of benzene, and exposing said aluminum chloride in contact with the paraffinic hydrocarbon and said benzene at a temperature in the range of about 40 to 300 F. to high energy ionizing radiation until a total dosage in the range of 10* to 10 kwh. of radiation energy per pound of paraffin has been absorbed.

3. A radiation isomerization process which comprises contacting normal hexane with 150 wt. percent based on the weight of hexane, of aluminum chloride, and exposing said aluminum chloride in contact with said hexane at a temperature in the range of about 40 to 150 F. at a pressure sufficient to maintain liquid phase conditions, to from about 10- to 10 megaroentgens of gamma radiation.

- 4. A hydrocarbon conversion process which comprises contacting a hydrocarbon feed comprising essentially paraffins having from about 4 to 8 carbon atoms under isomerization reaction conditions with a catalyzing amount of aluminum chloride in the presence of a total dosage in the range of 10- to 10 kwh. per pound of paraflin of high energy ionizing radiation.

5. A hydrocarbon conversion process which comprises contacting a hydrocarbon feed comprising essentially paraffins having from about 4 to 8 carbon atoms, with aluminum chloride present in the amount of about 2. to 200 wt. percent based on the weight of parafiin in the feed, and exposing the aluminum chloride in contact with said feed at a temperature of from about 40 to 300 F. to high energy ionizing radiation until a total dosage in the range of 10- to 10 kwh. of radiation energy per pound of parafiin has been absorbed.

6. A hydrocarbon conversion process which comprises contacting a hydrocarbon feed comprising essentially paraffins selected from the group consisting of nbutane, n-pentane, n-hexane, n-heptane, n-octane and mixtures thereof, with about 2 to 200 wt. percent based on the weight of parafiin in the feed of aluminum chloride, at a temperature of about 40 to 300 F., in the presence of high energy ionizing radiation until a total dosage in the range of 10'- to 10 kwh. of radiation energy per pound of parafiin has been absorbed.

7. A radiolysis process for converting paraflin hydrocarbons which comprises contacting a hydrocarbon feed comprising essentially paraffins having from about 4 to 8 carbon atoms per molecule with aluminum chloride present in the amount of about 2 to 200 Wt. percent based on the weight of parafiin, exposing the aluminum chloride in contact with said feed at a temperature of from about 40 to 300 F. to high energy ionizing radiation of intensity which is at least 1 10- kwh. per pound of hydrocarbon feed per hour until a total dosage of l0- to 10 kwh. of radiation energy per pound of paraffin has been absorbed, and recovering a converted prodnot.

8. A hydrocarbon conversion process which comprises contacting a hydrocarbon feed containing from about 0.1 to 10 parts benzene and from to 99.9 parts of a paraffin having from 4 to 8 carbon atoms per molecule with aluminum chloride present in the amount of about 2 to 200 wt. percent based on the weight of paraflin in the feed, and exposing the aluminum chloride in contact with said feed at a temperature of from about 40 to 300 F. to high energy ionizing radiation until a total dosage in the range of 10* to 10 kwh. of radiation energy per pound of parafiin has been absorbed.

9. In a continuous isomerization process in which a hydrocarbon mixture comprising norm-a1 parafiins having about from 4 to 8 carbon atoms per molecule is contacted under isomerization reaction conditions with an aluminum chloride catalyst, the step of exposing said catalyst during the isomerization reaction to a total dosage in the range of 10- to 10 kwh. per pound of paraffin of high energy ionizing radiation.

10. A conversion process which comprises charging a reactor with a paraffinic hydrocarbon having from about 4 to 8 carbon atoms per molecule and an aluminum chloride catalyst, exposing said catalyst in contact with said hydrocarbon to high energy ionizing radiation until a total dosage in the range of 10 to 10 kwh. per pound of parafiin has been absorbed, continuously removing a converted reaction product from the reactor, continuously separating the unconverted hydrocarbon from the desired isoparafiin product, recycling said unconverted hydrocarbon to said reactor, and continuously feeding a fresh supply of hydrocarbon to the reactor.

11. A continuous isomerization process which comprises passing a hydrocarbon feed stock containing at least 75 wt. percent of straight-chain paraflins having from 4 to 8 carbon atoms per molecule in contact with a slurry comprising an aluminum chloride catalyst through a reaction chamber wherein said catalyst in contact with said hydrocarbon feed is subjected to high energy ionizing radiation until a total dosage in the range of 10' to 10 kWh. of radiation energy per pound of paraffin has been absorbed and continuously separating and withdrawing an isomerized product.

12. A process according to claim 10 wherein said isoparaffin product is separated by absorption on a molecular sieve.

References Cited in the file of this patent UNITED STATES PATENTS 2,657,985 Schutze et a1. Nov. 3, 1953 5 OTHER REFERENCES Berkman: Catalysis, pp. 988 and 989. Quarterly Reviews, vol. 3 (1949), pages 293-95. Thomas: Anhydrous Aluminum Chloride in Or- 10 ganic Chemistry (1941), pages 787-788.

Proceedings of International Conference on Peaceful Uses of Atomic Energy, vol. 15 (1955), page 28. 

1. A RADIATION ISOMERIZATION PROCESS WHICH COMPRISES CONTACTING A PARAFFINIC HYDROCARBON HAVING FROM ABOUT 4 TO 8 CARBON ATOMS WITH ABOUT 2 TO 200 WT. PERCENT BASED ON THE WEIGHT OF PARAFFIN, A ALUMINUM CHLORIDE, AND EXPOSING SAID ALUMINUM CHLORIDE IN CONTACT WITH THE PARAFFINIC HYDROCARBON AT A TEMPERATURE IN THE RANGE OF ABOUT 40* TO 300* F. TO HIGH ENERGY IONIZING RADIATION UNTIL A TOTAL DOSAGE IN THE RANGE OF 10**-6 TO 40**3 KWH. OF RADIATION ENERGY PER POUND OF PARAFFIN HAS BEEN ABSORBED. 